Fuselage sections are often deformed when arriving to a final stage of an assembly process. The deformation usually consists of a distortion of a floor structure such that it is no longer straight. This warping or twisting of the component may occur during transport from the supplier to the assembly location. It may also occur as the component is placed on an assembly tool during the assembly process.
If ignored, using deformed components may lead to misalignments with other components and thus less aerodynamically-efficient aircraft. Special support structures may be constructed to ensure that a mounted component regains its initial shape, but this adds costs to the assembly process as it requires custom-made supports for each component. Manual reshaping procedures may be used before assembly to reshape deformed components, but this adds manpower and time to the assembly process.